5c:pretty tough =o 1) there should be 2 exits at the bottom left, so put on portal in each, then let go of the ball 2) The ball will bounce/roll and pass the 2 point
… things, and the moment it passes through the second, pause and restart the whole thing (this is to make sure the ball will fall straight). 3) move the left bottom portal,(which is facing right) to the top right exit (which is facing down), then let go of the ball. Let it go through the portal, and by the time it has gone through and is about to touch the bottom, pause the ball, and move the bottom left portal to the exit that is facing the other portal 4) let it gain some speed, and once it cant go much faster, pause the ball. 5) leave the bottom right portal alone, and move the other one at the bottom left, the exit *facing* the blackhole thing. The speed will catch it, and it will teleport the ball to the last point thing 6) reverse every thing to the start, and move the bottom right portal to the top left, the one almost facing the finish, then let go of the ball. (MORE) 
